// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/cert/merkle_audit_proof.h"

#include "base/logging.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace net {
namespace ct {
    namespace {

        TEST(MerkleAuditProofTest, CalculatesAuditPathLengthCorrectly)
        {
            // Test all leaves up to a tree size of 4:
            EXPECT_EQ(0u, CalculateAuditPathLength(0, 1));
            EXPECT_EQ(1u, CalculateAuditPathLength(0, 2));
            EXPECT_EQ(1u, CalculateAuditPathLength(1, 2));
            EXPECT_EQ(2u, CalculateAuditPathLength(0, 3));
            EXPECT_EQ(2u, CalculateAuditPathLength(1, 3));
            EXPECT_EQ(1u, CalculateAuditPathLength(2, 3));
            EXPECT_EQ(2u, CalculateAuditPathLength(0, 4));
            EXPECT_EQ(2u, CalculateAuditPathLength(1, 4));
            EXPECT_EQ(2u, CalculateAuditPathLength(2, 4));
            EXPECT_EQ(2u, CalculateAuditPathLength(3, 4));
            // Boundary cases for a larger tree size:
            EXPECT_EQ(9u, CalculateAuditPathLength(0, 257));
            EXPECT_EQ(9u, CalculateAuditPathLength(255, 257));
            EXPECT_EQ(1u, CalculateAuditPathLength(256, 257));
            // Example from CT over DNS draft RFC:
            EXPECT_EQ(20u, CalculateAuditPathLength(123456, 999999));
            // Test data from
            // https://github.com/google/certificate-transparency/blob/af98904302724c29aa6659ca372d41c9687de2b7/python/ct/crypto/merkle_test.py:
            EXPECT_EQ(22u, CalculateAuditPathLength(848049, 3630887));
        }

        TEST(MerkleAuditProofDeathTest, DiesIfLeafIndexIsGreaterThanOrEqualToTreeSize)
        {
#ifdef OFFICIAL_BUILD
            // The official build does not print the reason a CHECK failed.
            const char kErrorRegex[] = "";
#else
            const char kErrorRegex[] = "leaf_index < tree_size";
#endif

            EXPECT_DEATH_IF_SUPPORTED(CalculateAuditPathLength(0, 0), kErrorRegex);
            EXPECT_DEATH_IF_SUPPORTED(CalculateAuditPathLength(10, 10), kErrorRegex);
            EXPECT_DEATH_IF_SUPPORTED(CalculateAuditPathLength(11, 10), kErrorRegex);
        }

    } // namespace
} // namespace ct
} // namespace net
